Currently firmware uses 1 byte at 0x5F offset in RTC CMOS to get number of CPUs present at boot. However 1 byte is not enough to handle more than 255 CPUs. So add a new fw_cfg file that would allow QEMU to tell it. For compat reasons add file only for machine types that support more than 255 CPUs.
Signed-off-by: Igor Mammedov <imamm...@redhat.com> --- hw/i386/pc.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index c2cd5bd..2b5581a 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1235,9 +1235,11 @@ void pc_machine_done(Notifier *notifier, void *data) PCMachineState *pcms = container_of(notifier, PCMachineState, machine_done); PCIBus *bus = pcms->bus; + static uint16_t boot_cpus; /* set the number of CPUs */ - rtc_set_memory(pcms->rtc, 0x5f, pc_present_cpus_count(pcms) - 1); + boot_cpus = pc_present_cpus_count(pcms); + rtc_set_memory(pcms->rtc, 0x5f, boot_cpus - 1); if (bus) { int extra_hosts = 0; @@ -1258,8 +1260,16 @@ void pc_machine_done(Notifier *notifier, void *data) acpi_setup(); if (pcms->fw_cfg) { + MachineClass *mc = MACHINE_GET_CLASS(pcms); + pc_build_smbios(pcms->fw_cfg); pc_build_feature_control_file(pcms); + + if (mc->max_cpus > 255) { + boot_cpus = cpu_to_le16(boot_cpus); + fw_cfg_add_file(pcms->fw_cfg, "etc/boot-cpus", &boot_cpus, + sizeof(boot_cpus)); + } } } -- 2.7.4